import java.util.Scanner;

/**
 * Created with IntelliJ IDEA.
 * Description:
 * User: dell
 * Date: 2022-11-09
 * Time: 14:35
 */
public class sushu {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
            int n = scanner.nextInt();
            int i = 2;
            for(; i < n; i++){
                if(n % i == 0){
                    break;
                }
            }
            if( i == n ){
                System.out.println(i+"是素数!");
            }
        }

    }

